7 chord vamp - what to play?

simple, you just have to ask yourself 'where does D7 occur in diatonic harmony?' diatonic harmony is literally the harmony (chords) that are in a key. Every major scale has one dominant 7 chord that is diatonic, the V (five) chord. So ask yourself, what major scale has D as it's 5th degree? G. The notes of g major will be your meat and potatoes scale over D7.
Now because your vamping over D7, the D will be functioning as the tonic or tonal center (resting place)of the music, so you will be playing in a modal situation, namely d mixolydian. That is what a mode is, a change of tonic. So you can always remember whenever you encounter a dominant 7 vamp and want to play mixolydian, it will be your major scale down a 5th(or up a 4th) from the root of the chord.
Now, this isn't the only thing you can do, because dominant chords are found in other harmonized scales, like melodic minor, but if you are new to the above stuff that would be your starting point.
Also you can do the normal blues stuff over a dominant 7 vamp as well, just like you might play over a D7 as the I chord in a D blues.

 

ok, your initial post made it sound like you knew less than you do. You answered your own question in regards to the min7 vamp. You have a choice between all those minor modes! In that case look at it like this:
your dorian will have the 'best fit' in terms of intervals that will all sound more natural over the min7 1, 2, b3,4, 5,6,b7-all are nice as resolutions in one way or another. the aeolian will add the b6-which tends to want to pull down to the 5, and is generally less stable. It also sounds a bit more antiquated to my ear if I had to generalize. Phrygian will have the b6 and b2, giving it more tension than the others. It might sound ethnic or mediteranean to some folks, depending on one's associations.
Or you can hint at all 3 scales at different times if you choose, this is the fun of an open vamp.
Do not think of a mode as just the starting and ending note, this is a common issue with many people. What makes the modality is the relationship of the notes to the tonic in the particular musical passage. If I am vamping over d min7 and start my lines on A, I won't be playing A aeolian no matter how often I do it, I will still be playing d dorian and just starting lines on the 5th, because the harmony is really dictating D as the tonic. By thinking of d as the tonic however, it may better help you pick and choose your resolutions in relation to that tonic, to really bring out the color of the mode.

 

You should have a basic grasp of what Matt said above. Great stuff! From there, what I do is group chords and modes together. In any Maj key, the I, III and VI chords are virtually one and the same. They are all tonic (resting) chords. In the key of G these will be.............. G Maj7 (The I chord), B-7 (the III chord), and Emin7 (the VI chord). The other 4 remaining chords are grouped together as well... A-7 (II chord) CMaj7 (IV chord), D7 (V chord) and F#-7 flat 5) (VII chord). These are all dominant chords. Since the vamp is a D7 vamp, all the chords that are grouped with the D7 can be used. The D7 tells you the tonality is D7, so everyone is playing the same thing! You can now play D7 arpeggios, A minor arpeggios, CMaj 7 arps, and F#7 flat 5 arps, and they will all fit perfectly! This also means that the correct "mode" for each of those chords can be looked at as one mode. The correct modes for those chords are D Mixolidian, A Dorian, C Lydian, and F# locrean. Pat Martino looks at all those as just A Dorian. I happen to think just D Mixolidian, but we are both playing the EXACT same thing. Remember also you can play D Blues scale, D Major and minor pentatonic, and many other scales. While any one of these work, the more you mix them, the more interesting it gets. You can also play the Gmaj7, B-7 and E-7, but you have to be careful with them, as they will sound like you are playing in a GMaj7 vamp, which you are not! To learn TONS of interesting lines and musical ideas, pick up Miles Davis CD "Kind of blue", and listen to the song "So what". If I remember, its in D dorian, then just moves up a half step to Eb dorian. You will hear the soloists using all of the chords and arpeggios listed above, (And WAY more) and enough to spend an entire lifetime learning. This sounds a LOT more difficult than it is. Once you sit down for a few hours, you will start to see how they all relate. For me, the simpler the better, and frees up my mind to listen better, and concentrate on what I am hearing. (Unfortunately, thats usually not much.)

 

I already wrote this before seeing Tag's and Matt's answers. I'm saying the same thing but showing it another way.

There is more than one way to approach it.

1) The key of the piece or at least a section of the piece if it changes keys a lot. Ex ii-V-I in C = dm7 G7 C can handle major and minor C pentatonic. For something with a lot of changes like "Confirmation" you can play in F pentatonic all day and it works.

2) the mode/scale of the chord you are on - as suggested D dorian over dm7 G mixolydian over G7 C major over Cmaj7
or Bb minor pentatonic over G7#9 for a more outside sound.

3) a line you are playing - ex. Flintstones theme starting on G and worry more about finishing off the line than the underlying chords. Sometimes you get some really cool results from this. It's like looking at the big picture.

4) the note relationship to the chord. ex. I can play a b5,b9 over a dominant 7th chord. For G7 I know that is Db and Ab.

5) outline arpeggios - the chords you are playing

6) superimposed arpeggios - ex: F7 arpeggio over G7 (sounds cool if you do F7 then G7, then F7, then G7 etc.) or E7 arp over G7 accentuates the b9 and 13th.

7) F*it, just wail! Usually this works in conjunction with approach #4 for a landing note.

With all these approaches you are still using your ear as the discriminator as you suggest.

I find myself doing all approaches. When I get lost, I pop back into approach #1 or #5.

I like Tag's approach, the simplier the better. Joe Pass said the same thing.

 

All goog ideas here!
the neat thing about scales and other formulas are that they are ultimately just ways of breaking down combinations of 12 notes. Eventually you will want to be to the point where you see/hear a D7 chord and just know how all 12 notes will sound and feel over it. They all work in some context or another, it just depends on how much relative tension or release you want, and where the chord is coming from or going to. Sometimes a note will sound lousy to end on, but when another note is put in front of it, the note works. Its all about the combinations. I always tell my students to learn the scales, learn the arpeggios, learn as many permutations and interval combinations as possible, and eventually these things will blend together and you'll just think of ideas that fit within the tonality your playing in. That is when you play your best, when your not really thinking at all!

 

..and so, based on all of the above, you have to take a look at the whole progression and get a feel for where it's going and when.
When is it "home" and when is it "away"? When is a dominant chord static - like a groove, when IT'S "home" and when is it supplying tension so that it's gonna take us home to a Major or minor chord?
I look for ii-V's, for minor ii-V's, for any series of dominant chords, etc.

Also - the original melody is another clue as to how the parts function.

It's all about tension and release, setting expectations, then fulfilling them - or surprising the listener.

 

While I grasp everything said here, I still say music theory is too damn complicated. If we did away with the sharps and flats and just called the notes one through twelve it would be much easier for everyone one.

In a nutshell, you have 12 notes, 7 are diatonic and definetely work, of the other five, three will give you outside tones and the other two will sound wrong if applied incorrectly. In truth, you can use all 12 all the time, as long as the non-diatonic are strictly passing tones that have BRIEF duration. If you play a dog, bend it of slide up a fret to make it sound like it was on purpose and avoid that note next time through. With half was decent ears, you can play anything as long as you are always ready to slide when needed. Lots of people play wrong notes, they are known as accidentals, although there is no accident about them being there.

 

I would equate what you're saying to what I called:

7) F*it, just wail! Usually this works in conjunction with approach #4 for a landing note.

You explained it better.